Underfeed stoker.



E. '.l. HART.

UNDERFEED STOKER.

APPLICATION mit) Nov. 23,4915. RENEWED Nov. 23.19r6.

Patented Sept, 25, 19127.

3 SHEETS-SHEET 2 111,5 @Hot nog E. J. HART. I UNDERFEED sToKER.' v APPLICATION FILE NOV. 23, 1915. RENEWED NOV. 23,1916. Lg,

!ihwhwfrlf... M llrli `Patented Sept. 25, 1917.

3 SHEETS-SHEET 3.

nivrTun sTaTns TATTTTT naaien.,

nnwriva. HART, 0F PHILADELPHIe, rnnusvnveivre;

UNDERFEED sT'oKEn.

Application ined november 2.3, 1915,.,E1ia1 No. 62,944. Renewed Nnvember', .1&18- .Serial No.. 133,096.

i To all whom t may oneern:

Be it known that L-EDWIN J. HART, a eitizen of the .United vStates, residing at Philadelphia, in the county .of Philadelphia and State of Pennsylvania, have invented certain new and useful lImprovements in' Underfeed Stokers, of which the following is a specification.

My invention relates to improvements in underfeed stokers, the `object of the invention being to provide a stoker of the character stated which is adapted to burn mechanieallyfvarious grades of jbituminous coal smokelessly and efiieiently, and which can be manufactured. and sold at a reasonably small price, the 11p-keep of which will be reduced to a minimum and l preferably utilize the stolrer in connection with a blower fan, although it may be used without one if desired.

A further object is to provide a retort with a hollow partition .constituting an air 'chamber and dividing vthe retort into two compartments which permits the supplying of coal in "small quantities overa large area and reduces localized combustion to'a minimum.A lt also prevents the formationo]e large troublesome elinkers whiehare oommon with stokers in general use.

A further object is toprovide an im proved construction ofthe character stated which ma)1 be used under natural draft in the event of a mishap to the equipment, and which embodies in its construction many novel details which eoperate in the performance of improved functions.

With these and other objects in View, the invention consists in certain novel features of construction and combinations and arrangements of parts as will be more fully hereinafter described and pointed out in the claims.

In the accompanying drawings:

Figure 1 is a plan view.

Fig. 2 is a View in longitudinal section on` the lineQ-2 of Fig. 1'.

Fig. 3 is a view in transverse section on the line 3-3 of Fig. 1, i

Fig. 4 is a View in transverse section on the line 44 of Fig. 1. i

Fig. 5 is a fragmentary View in endelevation showing a portion of the stnuetuirewen an enlarged scale. 1

Fig.' .6 is a view in longitudinales ion through oneef the set .screws 43'.

Speeieatinn of Letters Patent. Patentd-Sept, 259 7, i

Fig.' 7 is a transverse sectional view through the tension plates 46.

Fig. 8 is a fragmentary .section onf-an en- Y larged scale ,taken longitudinally through .one of the grate bars adjacent the retort.

My improved stokergis provided .witha centralv longitudinal retort l Vdivided bya central longitudinal hollow partition 2 1011' stiitutmg an air chamber with perforations 2a in its side walls, so as to direct @the air;

into the fuel. f

The retort 1 is located above an air ,box 3 which communicates with air spaeesAf by means of openings 5. The air spaces 4e are formed between the sides of the airbex,V and longitudinal plates or partitions 6, the latter having wind gates 7 controlling openings 8 therein, and said wind gates operated .by rods 9 to regulate the passage of air from the air boX into air ehambers 10 belowthe grate bars 11.

Suitable gates in partition plates which' extenddoww close the air chamber 10, and IltO this charnber 10 line particles of uneonsumed fuel are adapted vto fall and may be removed Ifrom- 4by a roekeigshaft, and as there are .twain 12 normally close openings 'wardly from'the grate .pedestals 14 and inclined sets vof grate-bars, provide two rocker shafts 20.

Each alternate grate bar is provided with lugs 21 which Areceive the web 22 .of the rocker shaft, while the remaining grate bars have such lugs omitted'so that they are not v moved by the movementof theroeker shafts.

The grate bars are of the two part type in'which the lower member 23 constitutes an.

air chamber, and the upper member 24 which supports the fuel is provided with a stepped 'surface 25 having air .ports 26 in lthe sides thereof, so that the air is directed horizontally and 1n a great many dine jets to entirely consume the fuel.

Each lower. grate member 23 is provided with a Ipartition E23a which divides `.the air ,ehamben .provided by the member 98, into .two ,compartments 23h and .23 (see Fig. 3).

.ion

.The compartments23lJ are directly above the partitions Gand rockershafts 20 that any air passing upwardly through the spaces 4 will pass-directly. into the compartments 23h, while ythe compartments 23c will receive air directly from the air chambers 10.

Air outlet passages 23d extend outwardly from the compartments 23b iiito the chute 30. By this construction, including the partitions 23a. as labove described, the air is evenly distributed throughout the entire length of the grate' bars, so that each of the air ports 26 vas well as-the passages 23d receive a proper amount 'of air because the air enters vthe lower portions of the grates through a number of independent sources, namely, vthe air spaces 4 and the chambers 10.

The air is admitted to the box 3 through a duct 27 communicating preferably with some form of blower (not shown), and 28 is a damper operated by varod 29 to control the How ofaii` into theair box.

rlhe retort 1 communicates with an inlet chute 30 into which a hopper 31 discharges the fuel. 32 is a pusher which is connected to across headf33 lon arpiston rod 34, and operates to give the fuelits initial movement along the chute 30. `The rod 344` is operated by a piston 35 in a cylinder 36, and steam or othervfluid may be utilized as amedium for reciprocating the piston.

The pusher 32 is secured .to and reciprocates a pair 0f rods 37 located at oppositesides of the air partition 2 in retort 1, and boosters 38 are secured to the rods and cause the fuel to movelongitudinally of the retort as is well understood.

' Therocker shafts 20 above referred to are provided on their outer ends with rocker arms 39,' lthelatter having spherical ends40 which move in grooves 41 in pivoted plates `4t2-secured to the cross head 33. These piv- -oted plates. 42 are adjusted by set screws; 43 to vary the angular disposition oftheslots 41, and it will be understood that the longitudinal movement ofthe cross headimparts a rocking movement to the rocker 'shafts 2O1by reason of the engagement of arms 39 with slots 41.

mounted in suitable bearing bars 44,"and

Y doors 45 are provided above the grates to permit of hand stoking in the event of accident to theautomatic stoker, also'in the eventof' using anatural draft, the doors 18 and 19 will be opened but in most cases l prefer a vforce draft.

'To'hold 'thefseveral grate barsiin their properposition-:and to permit. a proper asl* senililagelutilize suitable tension plates 46 at one end ofeacli series of grate bars to 1 chamber below the chute,

inattesa hold'the grate bars against lateral move- Anient as shown clearly in the plan view Fig. 1.

Theoperation is as follows: Coal is fed mechanically or otherwiseiiito the hopper3l and is fed forward. in the' chute 30 by the reciprocation of the pusher 32, advancing the,c oal 'in the retort,'the

boosters38 assisting in this operation.v`

The rocker shafts 2O are .continuouslyrocked, and the/burningI fuel is caused to move along the grate bars until itfis consumed, when it falls onto the dump grates 15 and from time to time isdropped into the ash pit 17`belowthrough the medium of an andis directed through the hollow partition 2`intothe fuel at both sides thereof, and also flows through the-several ports and chambers above referred to, and supplies the necessary 'air for a good combustion.

A .As it is the purpose of my improved stoker to consume the fuel with as littlesinoke as possible, the arrangement of air supply ports is importantv because it distributes the air throughoutvthe fuel and provides the necessary oxygen to consume the coal.

All the parts are so arranged as to permit of an adjustment so as to suit the particular fuel consumed, and the parts are so con# structed and assembled that they can be readily removed and replaced when it is necessary. i

Various slight changes might be made in at liberty to make such changes and altera- .tionsas fairly fall within the spirit and scope of the appended claims.

. Y suitable mechanism controlling the shafts `16. 8G

Air entersv through duct 27 into air box 3,

Having thus described my invention, what lclaim as new and desire to secure by- Letters Patent is:

` 1. In a stoker of the character described,

the combination of a longitudinally extend-v ing chute, means providing an air supply a hollow partition extending longitudinally between the walls of said chute and communicating with said' chamber, fuel conveying ineans located between the walls of the chute and the opposite sides of the partition, said 'partition having air outlets leading into the fuel as it is conveyedin the chute, substantially as described.

2. ln a Stoker ofthe character described, the combination with a retort, and an air supply chamber below the retort, of a hollow partition constituting an air chamber extending throughout the center of the retorthavvi'ng air outlets in its sides and having open communication throughout its length with the air chamber below, and

1 igcecgcee A reciprocating boostersin theretort at opposite -sidesof the -rp artition, described.

3. En va vStoker of thel charfwterA described, 5 .thecombination withia retort, and an air supply chamber below the retort, oti'za hollow` partition constituting an air chamber yextending throughout the centerv of the retort having air outlets in its sides and having open :communication -throughout its vrlength -withtheI air chamber below, -a 'chute communicating with one' end of the retort,

a hopper communicating Awith the chute, and a reciprocating pusher below the hopvper forcingtlie fuel in the lchute into the retortat opposite sides o f the partition, substantially as described. i

fi. In a Stoker of the character described, -thecombination with-a retort, and an air supply chamber below .the retort, of a hollow partition constituting an air chamber extending throughout the center .of the reftert havingiair outlets in its sides and having open communication throughout its length with1the air chamber below, reciprocating boosters in lthe retort at opposite sides of 'thepartition7 a chute communicating with onexend of `the rctort,a hopper communi,- cating withthe chute,

inthe chute intothe retort at opposite sides ofthe partition, substantially as described. 5. In astoker ofuthecharacter described, the combination with a' retort, and an lair supply chambcrbelow the retort, of a hol- -low partition constituting an air chamber extendingthroughout.the center of the re- 'torthaving airoutlets in itssidesfand having open communication throughout its 40 Alength ywiththe air chamber below, inclined grate bars havingtheir highest ends located at the sides of the retort, means for forcing fuel longitudinally of the retort and over the sides of the retort onto the grate bars, means vfor shaking the grate bars, and a single motor simultaneously operating-both of said last mentioned means, substantially vas described. l 6. In a Stoker of thecharacter described, the combination with a retort, and inclined grate 'bars -at opposite sides thereof, of a hollow partition constituting an air chamber extending throughout'vthe center of the retort and having air outlet perforations in.

the sides thereof, an air box below the retort having open communicationv with the partition throughout the length of the vlatter, boosters .in the retort at opposite sides ot the partition, rocker shafts adapted to move the grate bars, and means for simultaneously reciprocating the boosters and oscillating the rocker shafts, substantially as described.

l 7 In a Stoker of the character described,

the combination with a retort, and inclined substantially as -tending'throughout the center'otthe retort,v

and a reciprocating 30 usher below the hopper -forcing the fuel grate hars at opposite sides thereof, ci a hollow ypartition constituting aniair charnber extending throughout lthe center nii-,the retort and having air outlet perforations in the sides thereof, 1anzfair boxbelow the re- 7c tort having open communication with-.the

`piston land operatively connected rto the pushers,rand means operatedv by the movement of the piston to oscillate the rocker arms, substantially as described. so 8.` in a stolrer of the character described, the combination with 'a Iretort and inclined ,gratos at opposite sidesthereof, of afhollow partition constituting .an air chamber eri:-

and having air outletperforations therein, an air box below 'the retort communicating with thepartition, walls spaced from the air boXand havingwind gates therein, and

said air box having openings communicating so with thespace between the saidwialls and `the boxand dircctingthe air into 'thegratea substantially, as described.

. 'ln a Stoker of the character described,

.the combination with a retort and inclined-e5v gratos-at opposite sides thereof, Lof a hollow partition constituting anl air ychamber extendingithroughout the center ofthe retort, and havingair outlet.perforations therein,reciprocating boosters in theretort '100 -at-opposite sides of the partition, an air ;boX below the retort communicating with the partition, .walls spaced from the air vboit and vhaving wind gates therein, 4and said airV box 'having openings communieating-with the space between the said'fwalls and the box and directing the air into the gratos, substantially as described; y

10. In an underfeed Stoker, the combination with a longitudinal retort, and inclined gratesat opposite sides thereof, 'of fa hollow. partition extending longitudinally of the retort and having4 air outlets in its walls, and anair box below the retort directing air into the partition and haviug-pas-Irio sages at the sides of the box yfor directing airthroughthe .grat-e bars atopposite sides of the retortsubstantially asdescribed.

11. In an underfeedstokor, the combination with a retort and inclined grate bars at opposite sides of the retort, rocker shafts constructed to move certain of the grate bars, a chute communicating with the retort,` `a hopper communicating with the chute, a pusher in the chute constructed lto move the fuel into the retort, a cross head operating the pusher, plates adjustably mounted on the cross head and having slots therein, arms on the rocker shafts located in the slots, and means for adjusting the plates 13o to vary the angular disposition of the slots, whereby the rocking movement of the rocker shafts is controlled, substantially. as de; scribed.

12. In an underfeed stolzer, the combination with a retort and inclined grate bars at opposite sides of the retort, rocker shafts constructed to move certainfof the grate bars, a chute communicating with the retort, a hopper communicating with the chute, a -pusher in the chute constructed to move the fuel into the retort, va cross head operating the pusher, plates adjustably mounted on the cross head and having slots therein, arms on the rocker shafts located in the slots, means for adjusting the plates to vary the angular disposition of the slots, whereby the rocking movement of the rocker shafts ,is controlled, a fluid cylinder, a 4piston in the cylinder, and a rodconnecting the piston with the cross head, substantially as described.

13. In an underfeed stoker, the combination with a retort, of vinclined grate bars at opposite sides of the retort, supporting means for the grate bars, each of said grate bans including an elongated air -chamber on their under face, and an upper face of stepped formation, each of said grate bars also having a partition' separating its air chamber into two compartments, and means below thev grate bars providing two air chambers, one o f said latter air chambers being directly below similaroompartments of the grate bars while the' other of said air chambers; is directly -below the other compartments of'said grate bars, each of said grate bars having ducts leading from one of said compartments to direct the air substantially horizontally, said grate bars each having passages leading from the other compartment into the retort, substantially as described.

lllfln an underfeed Stoker, the combination With a retort, of inclined grate -bars at` dppositesides of the retort, each of said grate bars being made in two elongated sections, one of .said sections having its upper surface arranged in stepped formation and provided with a seriesl of openings for `di- 'rectingiair horizontally, the other of said :sections'fforming a support for the firstmentioned sections and providing an Aelongated alr chamber. partitions m said second the sections dividingl the 'air` chamber into two compartments, means forsupporting the second grate sections and including a partition in substantial alinement with thepartitions of said grate sections and yforming two air spaces, one for directing air into,` slmilar compartments of each grate bar seotion, the other of said latter air chambers being located to direct air into the other compartments, and passages leading from atter compartments in each grate bar andl opening into. the retort, substantially vas described. 1 .l

15. In an underfeed stoker, the combination with a retort, of inclined grate bars, eachof said grate bars made intwo sections, one of said sections having its upper surface arranged in stepped formation and pro- 'vided with a series of openings for directing air horizontally, the lother of said sections being of greater length than the lirstthe uppermost compartments"intoI the retort, substantially as described.

v7162 In an under-feed stolzer, the combination witha retort, and grate bars at oppos` site sides thereof, of rocker shafts, arms on the rocker shafts constructed toshale the grate bars, a reciprocating member, plates pivotally supported on vthe reciprocating member and having slots therein receiving the ends'of said arms, and means for adjusting the plates to varyv the angular disposition of the slots, whereby the movement. l

of the rocker shafts is as described. 1 l 'In testimony whereof I have signed my name to this. specification in the presence of two subscribing witnesses. l

EDWIN JHART."

varied, substantially Witnesses:

CHs. E.' Por'rs, Mann, JACKSON. 

